1. Field of the Invention
The present invention relates to a flexible wiring board having a flexible portion and a method of manufacturing the flexible wiring board.
2. Discussion of the Background
A flex-rigid wiring board, a part of which has rigidity, and the other part of which has flexibility, is described, for example, in Japanese Unexamined Patent Application Publication Nos. 2006-140213 and 2006-100703, and PCT International Publication WO2004/093508.
A flex-rigid wiring board described in Japanese Unexamined Patent Application Publication No. 2006-140213 has core boards which are rigid portions, a flexible board disposed adjacent to the core boards in a horizontal direction, flexible adhesive layers laminated on the core boards and the flexible board, wiring patterns formed on the flexible adhesive layers located on the rigid portions, and blind vias and/or through-holes connecting the wiring patterns formed on individual layers. In the structure described above, the flexible adhesive layer is laminated on the flexible board.
Japanese Unexamined Patent Application Publication No. 2006-100703 describes a method for manufacturing a flex-rigid wiring board. In that method, first, rigid boards each having a vertical wiring portion in a connection region and a flexible board having connection terminals formed at end portions are separately formed. Subsequently, the connection regions of the rigid boards are each machined to form a cut-off portion having a depth larger than the thickness of the flexible board, thereby forming steps. Next, the connection terminals of the flexible board are connected to the vertical wiring portions at the steps.
A flex-rigid wiring board described in PCT International Publication WO2004/093508 includes a rigid board and a flexible board which are bonded with an insulating adhesive interposed to form a unified body. In addition, connection electrode pads of the rigid and flexible boards are electrically and physically connected to each other through with a conductor block and penetrating through the insulating adhesive. In the flex-rigid wiring board having the above structure, the flexible board is disposed on one side of the rigid substrate, a via is formed by laser irradiation, and connection is formed by plating from the flexible board side.
The contents of the above mentioned publications are incorporated herein by reference in their entirety.